I bought a Dahon D7 Vitesse 2008 which fits nicely into the boot of my car. I'm also looking at buying a Dahon Jack. Given that these have 26" wheels and won't fold so well do they still fit in cars? I have a Hyundai coupe but I can put the seats forward to enlarge the boot/trunk space.
The Jack folds to half of the size of a normal MTB, and is designed so that removing just the front wheel doesn't really shrink it's profile anymore that that (half of MTB). However, by either removing the front wheel or the handle bars, you can reduce the width quite a bit (50%) because the handle bars are the widest point.
In a Toyota Camry trunk, I didn't have to remove anything, the width was exactly right and snug (handlebar length ~= trunk height). There was plenty of room on the sides and maybe a foot to spare front to back.
I folded my Cadenza 8 for the first time yesterday to stash it in a friends car boot. It fitted without any problems (after removing the stem/bars) but the most sticky-outy bit was the steerer tube.
I have about 3cm of excess and Im considering cutting it down a bit. I have already flipped the stem for a lower position so I could flip it back if I ever needed more height. There is also the safety aspect of riding around with 3cm of steerer above the stem. The NVO steerer collar would need cutting back but NVO have good instructions. Ho hum....